package com.igd.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

 /**
 * @version  1.0
 *
 * @author   QIAOYU
 *
 * @date     2013-6-18
 *
 * @description	 随机认证码工具类,包含认证码生成与认证码的验证
 */

public class RandomCodeUtil {

	private Random random = new Random();
	
	/** 随机产生的字符串 */
    private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    
    private int width = 80;//图片宽
    
    private int height = 26;//图片高
    
    private int lineSize = 40;//干扰线数量
    
    private int stringNum = 4;//随机产生字符数量
    
    /*
     * 获得字体
     */
    private Font getFont(){
    	
        return new Font("Fixedsys",Font.CENTER_BASELINE,18);
        
    }
    
    /*
     * 获得颜色
     */
    private Color getRandColor(int fc,int bc){
    	
        if(fc > 255){
        	
        	fc = 255;
        	
        }
            
        if(bc > 255){
        	
        	bc = 255;
        	
        }
            
        int r = fc + random.nextInt(bc-fc-16);
        
        int g = fc + random.nextInt(bc-fc-14);
        
        int b = fc + random.nextInt(bc-fc-18);
        
        return new Color(r,g,b);
    }
    
    /**
     * 生成随机图片
     * 
     * @param request
     * 
     * @param response
     * 
     * @param randomKey 传入Session中存入的随机值的KEY
     * 
     * @throws IOException 
     */
    public void getRandcode(HttpServletRequest request,HttpServletResponse response,String randomKey) throws IOException {
    	
        HttpSession session = request.getSession();
        
        /** BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类 */
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);
        
        /**产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作*/
        Graphics g = image.getGraphics();

        g.fillRect(0, 0, width, height);
        
        g.setFont(new Font("Times New Roman",Font.ROMAN_BASELINE,25));
        
        g.setColor(getRandColor(110, 133));
        
        //绘制干扰线
        for(int i=0;i<=lineSize;i++){
        	
        	drawLine(g);

        }
        
        //绘制随机字符
        String randomString = "";
        
        for(int i=1;i<=stringNum;i++){
        	
            randomString = drawString(g,randomString,i);
            
        }
        
        session.removeAttribute(randomKey);
        
        session.setAttribute(randomKey, randomString);
        
        g.dispose();
        
      //设置相应类型,告诉浏览器输出的内容为图片
        response.setContentType("image/jpeg");
        
        //设置响应头信息，告诉浏览器不要缓存此内容
        response.setHeader("Pragma", "No-cache");
        
        response.setHeader("Cache-Control", "no-cache");
        
        response.setDateHeader("Expire", 0);
        
        //将内存中的图片通过流动形式输出到客户端
        ImageIO.write(image, "JPEG", response.getOutputStream());

    }
    
    /**
     * 绘制字符串
     * 
     * @param g 绘图对象
     * 
     * @param randomString 绘制的随机值
     * 
     * @param i 横向坐标值
     * 
     * @return
     */
    private String drawString(Graphics g,String randomString,int i){

        g.setFont(getFont());

        g.setColor(new Color(random.nextInt(101),random.nextInt(111),random.nextInt(121)));
        
        String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));

        randomString +=rand;

        g.translate(random.nextInt(3), random.nextInt(3));

        g.drawString(rand, 13*i, 16);

        return randomString;
    }
    
    /**
     * 绘制干扰线
     * 
     * @param g 绘图对象
     */
    private void drawLine(Graphics g){
    	
        int x = random.nextInt(width);
        
        int y = random.nextInt(height);
        
        int xl = random.nextInt(13);
        
        int yl = random.nextInt(15);
        
        g.drawLine(x, y, x+xl, y+yl);
        
    }

    /**
     * 获取随机的字符
     * 
     * @param num 随机字符串长度之内的随机数
     * 
     * @return
     */
    public String getRandomString(int num){
    	
        return String.valueOf(randString.charAt(num));

    }

	public String getRandString() {
		return randString;
	}

	public void setRandString(String randString) {
		this.randString = randString;
	}

	public int getWidth() {
		return width;
	}

	public void setWidth(int width) {
		this.width = width;
	}

	public int getHeight() {
		return height;
	}

	public void setHeight(int height) {
		this.height = height;
	}

	public int getLineSize() {
		return lineSize;
	}

	public void setLineSize(int lineSize) {
		this.lineSize = lineSize;
	}

	public int getStringNum() {
		return stringNum;
	}

	public void setStringNum(int stringNum) {
		this.stringNum = stringNum;
	}
}
